Ulster took a huge step towards the semi-finals of the Guinness PRO12 with a commanding 30-6 win over interprovincial rivals Leinster at the Kingspan Stadium.

A controversial penalty try in the first half along with tries from Jared Payne and Paddy Jackson, who added 13 points with the boot, were enough to see the hosts pick up the four match points.

Leinster were thoroughly outplayed, their only points coming from the boot of Jonathan Sexton, by a well-drilled and resolute Ulster defence that kept them out time and time again and didn’t allow them a try in the game.

It was the hosts who got the scoring underway in the 11th minute when Luke McGrath clearly impeded Andrew Trimble’s attempt to challenge for an aerial kick and Jackson slotted over the resulting penalty in front of the posts.

If that obstruction cost the visitors, their second cost them even more as Rob Kearney body checked Ruan Pienaar after the scrum-half broke through the line and chipped over the top.

After a lengthy debate, Kearney was given a yellow card for his misdemeanour and referee George Clancy went under the posts for what seemed to be something of a fortunate penalty try to the hosts.

Despite being a man down, Leinster were the better side during the sin bin period and they deservedly got their first points of the game during that time through a Jonathan Sexton penalty in the 27th minute.

Back to full strength Leinster started to string a few moves together and Sexton landed another penalty from the touchline just before the break reducing Ulster’s lead to just 10-6 at the half-time interval.

After the break it was fairly even with both side passing up good opportunities to score tries from a set piece – Ulster from their weaker scrum and Leinster from their impressive maul.

But it would be Leinster’s discipline that would let them down again, this time substitute Luke Fitzgerald, only on the pitch for three minutes, guilty of pulling back Rory Scholes following Stuart McCloskey’s initial break.

Jackson added the penalty given for the offence and the hosts knew they had to make amends for the last time they were down a man, and they did.

With the extra man, the home side set up a driving maul that Leinster had to put extra men into to defend and with the space available out wide the passes went through the hands to Jared Payne who slid over for the 58th minute try.

Now with a commanding lead, Ulster set about defending it and they did so resolutely as they continued to repel the repeated Leinster attacks in a strong defensive showing.

And in the last ten minutes Paddy Jackson made sure the game was secure with his final penalty of the game and he also rounded it off with a try to make his day complete.

Having slotted the penalty with ten minutes to go, Jackson intercepted a short floated pass on the 22 metre line from Eoin Reddan and ran the length of the pitch to dot down for a try his performance deserved.

There was still time for Ulster to potentially snatch a try bonus point at the death, however Rory Scholes couldn’t hold Darren Cave’s pass mere metres from the try line meaning Les Kiss and his team would have to settle for just the four point win.